Exactly what are pocket springs? Are they mini mousetraps that you keep in your pockets ready for the moment when you’re exceedingly bored and need something to wake you up? No, they are “de rigueur” in modern mattresses, the idea being that a person can move and turn in bed without disturbing his or her partner (unlike one of our old mattresses, which shakes like a gigantic jelly at the slightest movement… and Chris has restless legs!). Anyway, the more pocket springs, the merrier – and the more expensive. Recently Chris and I splashed out on a new pocket spring mattress and a cheap, but attractive, bed frame.

“I could just lie here and go to sleep,” says Mary.

“So you don’t think it’s too hard then?” I ask.

It is three o’clock in the afternoon and my sister and I are lying on the new bed in one of our guest bedrooms at the top of the house, testing it for comfort and strength (the bed, not the house). I have been a bit worried about the new pretty white bed since we purchased it, really cheaply; in fact, we went back to the store twice with questions about its credentials and fitness for purpose. Wouldn’t it be terrible if the bed collapsed under the strain of a well-built couple at a crucial moment? Which has happened at least once (to my knowledge) to my brother Henry and his girlfriend in Australia. But the man in the bed department assured Chris and me that our remarkably cheap bed was the strongest metal bed in the whole store. But is it comfortable?

“It’s ever so comfy,” Mary closes her eyes.

“The mattress has pocket springs,” I comfort myself, “but there isn’t much bounce – is there?”

“Good for sleep,” Mary catches my drift.

“And what about other things?” I query with a smile.

We’re rather weary after traipsing up to the top floor (fifty one steps from the ground floor) so it is with some effort of will that my sister and I muster the energy to attempt to make the mattress bounce. Soon we tire of the futile exercise and lay back languidly on the lifeless, but dreamily comfortable, pocket spring mattress.

“Oh dear,” I say, “not the best for love-making…”

“That’s not your worry, Sally,” Mary opens her eyes and smiles mischievously, “besides, the big lovers can sleep on Dad’s old bed – with the wobbly mattress – in the next room. And anyway, you have to remember the kids are a lot younger than us.”